build: Add more Meson options for disabling parts of the build

This is all aimed at making it so that sysprof can be built as a
subproject within GLib, with only `libsysprof-capture-4.a` being
produced as output.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

examples/meson.build

@@ -1,3 +1,7 @@
+if get_option('enable_examples')
+
 app = executable('example-app', 'app.c',
   dependencies: [dependency('glib-2.0'), libsysprof_capture_dep],
 )
+
+endif

meson_options.txt

@@ -32,3 +32,15 @@ option('help', type: 'boolean')
 
 # Disable use of libunwind
 option('libunwind', type: 'boolean')
+
+# Optionally disable the tools (this is mostly only useful for building only
+# libsysprof-capture as a subproject)
+option('enable_tools', type: 'boolean')
+
+# Optionally disable the tests (this is mostly only useful for building only
+# libsysprof-capture as a subproject)
+option('enable_tests', type: 'boolean')
+
+# Optionally disable the examples (this is mostly only useful for building only
+# libsysprof-capture as a subproject)
+option('enable_examples', type: 'boolean')

src/tests/meson.build

@@ -1,3 +1,5 @@
+if get_option('enable_tests')
+
 test_env = [
   'G_TEST_SRCDIR="@0@"'.format(meson.current_source_dir()),
   'G_TEST_BUILDDIR="@0@"'.format(meson.current_build_dir()),
@@ -147,3 +149,4 @@ if get_option('enable_gtk')
 
 endif
 endif
+endif

src/tools/meson.build

@@ -1,3 +1,5 @@
+if get_option('enable_tools')
+
 tools_deps = [
   dependency('glib-2.0'),
   libsysprof_capture_dep,
@@ -42,3 +44,5 @@ list_threads = executable('list-threads', ['list-threads.c'],
         c_args: tools_cflags,
        install: false,
 )
+
+endif